Does optic nerve vasculitis mean I have lupus?

No. Vasculitis of the actual nerve is very very rare. More likely things are nerve swelling ie pseudotumor cerebri, or papilledema. The answer is in the actual findings on opthalmologic tests and patient should be seen both by a rheumatologist and a neuro-opthalmologist. Treatment for actual vasculitis is more difficult, and the diagnosis usually requires a cerebal blood vessel angiogram.